Full-Filling Subcarrier Power Allocation in OFDMA-Based Cognitive Radio Systems

Tuan Le Van, Hieu Dinh Chi, Kinh Nguyen Viet, Hieu Nguyen Thanh

Authority of Radio Frequency Management, Hanoi, Viet Nam.
School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore City, Singapore.
University of Engineering and Technology, Hanoi, Viet Nam.

DOI: 10.4236/wet.2014.51002                

Abstract

When implementing an appropriate windowing, the interference from a Cognitive Radio (CR) system to licensed systems (primary users) will be significantly reduced. Consequently, power allocated to subcarriers can be increased, especially subcarriers having far spectral distance to primary user bands can be allocated full of its maximum possible power. In this paper, we propose a new class of sub-optimal subcarrier power allocation algorithm that significantly reduces complexity of OFDMA-based CR systems. Two sub-optimal proposals, called Pre-set Filling Range (PFR) and Maximum Filling Range (MFR) are studied. Investigations show that this new power allocating algorithm allows CR systems obtain high throughput while retaining low complexity.

Keywords

Cognitive Radio; Windowing; Power Allocation; Full Filling

Conflicts of Interest

The authors declare no conflicts of interest.

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